This invention relates to compositions for coloring keratin fibers which contain special derivatives of benzo[b]furan-3-one and/or benzo-[b]-thiophen-3-one and reactive compounds, to a coloring process using this dye precursor combination and to the use of this combination for coloring keratin fibers.
Nowadays, human hair is treated in many different ways with hair-care preparations. Such treatments include, for example, the cleaning of hair with shampoos, the care and regeneration of hair with rinses and treatments and the bleaching, coloring and shaping of hair with coloring and tinting formulations, wave formulations and styling preparations. Among these, formulations for modifying or shading the color of the hair occupy a prominent position.
Colorants or tints containing substantive dyes as their coloring component are normally used for temporary colors. Substantive dyes are based on dye molecules which are directly absorbed onto the hair and do not require an oxidative process for developing the color. Dyes such as these include, for example, henna which has been used since ancient times for coloring the body and hair. Corresponding colors are generally sensitive to shampooing so that an often unwanted change of shade or even a visible “decoloration” can occur.
So-called oxidation colorants are used for permanent, intensive colors with corresponding fastness properties. Oxidation colorants normally contain oxidation dye precursors, so-called primary intermediates and secondary intermediates. The primary intermediates form the actual dyes with one another or by coupling with one or more secondary intermediates under the influence of oxidizing agents or atmospheric oxygen. Oxidation colorants are distinguished by excellent long-lasting coloring results. Natural-looking colors normally require a mixture of a relatively large number of oxidation dye precursors; in many cases, substantive dyes are used for shading.
Finally, a new coloring process has very recently attracted considerable attention. In this process, precursors of the natural hair dye melanin are applied to the hair. These precursors then form “nature-analogous” dyes in the course of oxidative processes. One such process using 5,6-dihydroxyindoline as the dye precursor is described in EP-B1-530 229. Another new coloring system is described, for example, in EP-A2-359 465. In this process, selected isatin derivatives are reacted with aromatic amines in the coloring of keratin fibers.
Nevertheless, there is always an ongoing search for other coloring systems which give intensive colors of the fibers with excellent fastness properties.